By Paul McLearyPaul McLeary is Foreign Policy’s senior reporter covering the U.S. Defense Department and national security issues. He joined the Washington office in 2015 after working for Defense News, where he was also on the Pentagon beat, and covered stories relating to Pentagon spending and the defense industry. While there, and in a previous incarnation as a New York-based reporter, Paul embedded with U.S. Army and Marine Corps units in Iraq and Afghanistan to cover ground combat operations, where he got inside a secretive drone program being run out of Bagram air base. He has also traveled with the U.S. Navy, covered NATO meetings in Europe with the chairman of the Joint Chiefs of Staff, and stalked major international arms shows in Paris and London.

U.S. knocks down Syrian bomber. A U.S. Navy F-18 shot down a Syrian Su-22 bomber near Raqqa on Sunday, throwing down an unambiguous new marker for forces who attack U.S.-backed fighters in the country: Washington will defend its allies.

The incident came after Syrian planes bombed U.S.-backed Syrian Democratic Forces (SDF) pressing on the ISIS stronghold of Raqqa. It’s the fourth time U.S. warplanes hit Syrian or “pro-government” forces (read: Iranian-backed Hezbollah and Shiite militias) in recent weeks, marking an increasingly hot new front in the almost three-year old U.S.-led bombing campaign in Syria.

The American action came after the SDF was attacked by government forces near the town of Taqba, prompting the U.S. military to use a “deconfliction” channel to communicate with Russian military officials to warn the Syrians off, the Pentagon said. The U.S. then flew a “show of force” mission to warn the fighters off. Hours later, a Syrian SU-22 bomber struck near the SDF, prompting the American shootdown.

Not the first time. U.S. warplanes bombed Iranian-backed Hezbollah fighters and other forces three times over the past month, after they moved too close to a U.S. garrison at al Tanf near the Iraqi border. Earlier this month, an Iranian-made drone bombed U.S. forces on patrol with their Syrian allies near the base, causing no injuries but prompting a U.S. F-15 to shoot the drone down. In April, American ships launched 59 cruise missiles at a Syrian air base in response to Syrian government chemical weapons attacks on civilians.

Warning shot. Just last week, a U.S. military officer told FP U.S. forces won’t hesitate to hit Iranian proxies if American special operations forces are endangered. “If our folks are on the ground and they’re threatened, we will use air power, whether it’s against regime forces or pro-regime forces,” the officer said.

War with Iran debated in White House. The incident underscores a sharp policy disagreement taking place at the White House over how forcefully to confront Iran and its proxies in Syria. The back and forth pits civilian hawks in the White House vs. Defense Secretary Jim Mattis and the Pentagon brass, who want to take a more measured approach.

The hawks are being led by Ezra Cohen-Watnick, the senior director for intelligence on the National Security Council, and Derek Harvey, the NSC’s top Middle East advisor, according to Kate Brannen, Dan De Luce and Paul McLeary, in a piece FP co-published with Just Security. The duo “want the United States to start going on the offensive in southern Syria, where, in recent weeks, the U.S. military has taken a handful of defensive actions against Iranian-backed forces fighting in support of Syrian President Bashar al-Assad. Their plans are making even traditional Iran hawks nervous, including Defense Secretary James Mattis, who has personally shot down their proposals more than once, the two sources said.” Read the rest here.

Some relief for al Tanf. The American garrison at al Tanf, which houses about 150 American Special Operations Forces along with commandos from allied countries partnering with Syrian Arab fighters, got some relief over the weekend, when Iraqi forces on the other side of the border cleared ISIS from a nearby border crossing.

Tragedy at sea. A U.S. Navy destroyer collided with a container ship early Saturday, killing seven sailors. The USS Fitzgerald was sailing off the coast of Japan, near Yokosuka, when it was struck, triggering what U.S. 7th Fleet commander Vice Adm. Joseph Aucoin called “heroic efforts” by the crew to save the ship from sinking as water poured into its berthing compartments.

Afghanistan. The Pentagon announced last week that SecDef Jim Mattis had been given the authority by President Donald Trump to determine the size of the U.S. troop commitment in Afghanistan. The unprecedented step comes from a White House that has shown itself to be very comfortable with delegating the running of the wars in Iraq, Syria and Afghanistan, as well as commando raids and air strikes in Somalia and Yemen, to Pentagon brass and commanders in the field.

The new Afghan strategy, according to military officials, will likely involve giving commanders on the ground more authority to deploy troops as they see fit, allowing them to embed with Afghan army units in the field to assist in calling in air support, and offer tactical advice. “That training mission will likely resemble in some ways what U.S. forces are doing in Iraq and Syria. There, American advisors are working with Syrian rebel commanders and Iraqi army officers to formulate battle plans and direct the fight around Mosul and Raqqa,” FP’s Paul McLeary writes.

The New York Times Mark Landler and Michael Gordon write, “it is not clear what Mr. Trump’s view of the strategy is, or even how involved he is in the debate. Officials said he did attend two National Security Council meetings last week — the first to discuss the troop issue, and the second to discuss the broader policy for South Asia.

Mr. Trump has said virtually nothing about Afghanistan since he was elected, or even since he started his campaign. But his views on the issue, based on Twitter posts when he was a private citizen, are uniformly hostile to America’s involvement in the war.”

Welcome to SitRep. Send any tips, thoughts or national security events to paul.mcleary@foreignpolicy.com or via Twitter: @paulmcleary or @arawnsley.

Iran fires missiles. Iranian Revolutionary Guards launched several mid-range ground-to-ground missiles from western Iran into eastern Syria over the weekend, claiming to have killed a “large number” of Islamic State terrorists and destroying their equipment and weapons. The strike was in response to the ISIS attack on Iran’s parliament and a shrine in Tehran earlier this month.

Strange bedfellows. The Israeli military has struck up a relationship with Syrian rebel groups along its northern border in an attempt to create a buffer between it and Assad regime and Iranian-backed forces, according to a scoop from the Wall Street Journal. Israel has paid senior commanders of groups like Fursan al-Joulan and established communication links to rebels dating back to at least 2013. Israeli officials claim that the payments are intended as a form of humanitarian assistance to rebels on its Golan border but rebels tell the Journal that they use the money to buy arms and ammunition.

Forecast. As if the airspace around Syria weren’t busy enough with military activity these days, Russia has issued a Notice to Airmen warning that the Russian Navy will carry out “rocket test firings” off the Syrian coast and south of Latakia on Monday.

Suwalki is the new Fulda. NATO carried out its first exercise simulating a defense of the Suwalki Gap, the narrow strip of Polish and Lithuanian territory that planners believe Russia would to capture in order to cut off the Baltics from the rest of NATO territory in the event of war. Reuters reports that the exercise involved 1,500 troops from the U.S., U.K., Poland, Lithuania, and Croatia. Russia will likely follow up the exercises with a drill of its own in Belarus in the coming weeks. While you’re reading, remember FP’sprevious explainer about the importance of the gap.

Wait a minute, Mr. Postman. The U.S. and North Korea had a minor scuffle over a package carried by a North Korean official at John F. Kennedy Airport on Friday. North Korea’s state-run KCNA news outlet complained that Homeland Security officials “literally mugged” their officials, forcibly taking a package from them. The Department of Homeland Security, however, claims that the North Korean officials involved were not accredited diplomat and the package they seized was not entitled to the protection of a diplomatic pouch.

Mali. Islamist terrorists in Mali killed two people at a tourist hotel near Bamako, the BBC reports. Malian and French special operations forces along with UN troops responded to the attack, leading to a firefight with the two attackers in which one of them escaped. The attack follows a 2015 assault on the country’s tourism industry, when militants from al Qaeda in the Islamic Maghreb and Al Mourabitoun mounted a mass shooting attack against the Radisson Blu hotel in Bamako. An Islamist insurgency in 2013 prompted France to intervene with airstrikes and troops in order to halt the militants’ advance. Militants from al-Qaeda in the Islamic Maghreb and Al-Mourabitoun also mounted an atta

Personnel. The Trump administration might have another senior position to fill in the Defense Department if Pacific Command commander Adm. Harry Harris leaves in 2018. Two sources tell Reuters that Harris is expected to depart after three years serving as Pacific Command chief, in line with the tenures of other combatant commanders. A Defense Department spokesman, however, says that no decisions about Harris’s future have been made and the Trump administration has not moved to select a successor.